The sentence that contains a predicate adjective is A. Jerry looks ill today. A predicate adjective is the first adjective following a linking verb such as to be, or to look, in this case. The word "ill" is an adjective and it follows the verb looks. B is incorrect because "at the map" is a prepositional phrase. C is incorrect because "disdainfully" is an adverb, not adjective. D is incorrect because "into the microscope" is also a prepositional phrase, given that it starts with a preposition.
